126 Journal of the Asiatic Society of Bengal. {N.S., XVIUHBH, 
conclusion however, while it clears the ground of a misconcep- 
tion which has hitherto misled experimental effort and vitiated 
inferences drawn, does not by itself assist us much in 
connection with the larger problem as to whether the urine is 
rival modified theories of Ludwig and Bowman, since it is now 
useless to say, e.g. that a kidney with a ligatured renal afferent 
vein is thereby deprived of three-quarters of its total blood 
supply and that since its tubules evidently cannot excrete as 
much urine from the intertubular blood under these conditions 
as the normal kidney with a venous supply, therefore the 
excess of urine excreted by the ligatured kidney in the 
experiments described above is definitely in favour of the 
n (the artificial 
>? 
tular-filtration and tubule-absorption theory of Ludwig (the 
neo-Ludwig theory as I shall call it), so ably put forward by 
Cushny (17), the mere facts that dye, potassium ferrocyanide 
veins at normal pressure without appearing in the urine 
(Part I) prove nothing, because if the tubules are absorptive, 
the presence of these substances even in the intertubular 
plexus will not affect the urine filtered from the glomeruli, 
provided that we assume, as Cushny assumes, that the absorp- 
tive activity of the tubules is independent of the constitution 
of the blood supplying them. Now we have seen that this 


' We can hardly calla theory which regards the glomerulus as a mere 
rete mirabile devoid of any filteri ; " 
. : an ; 
on the other hand, neo-Lu preferable : the expression ‘‘ modern” 
coined by Cushny for his modification of Ludwig’s theory. since the latter 
term begs the question. The eo-Ludwig theo - 
pie that of wig in assuming that the tubule cells absorb ke's 
re ool the Tubule one bc - ry. on the other hand, differs from that 
f Bowman itting one half of *si 
nism for the pecdaction of urine. Den ee eee ae 


